1. Field of the Invention
This invention relates to a linear sliding variable resistor for use in a position detecting sensor for example.
2. Description of Related Art
The general structure of a linear sliding variable resistor known as a conventional example is shown in the side sectional view of FIG. 5. The linear sliding variable resistor is comprised of a case 23 having a through hole 21 in one end face and an opening 22 in the opposite side surface, an operating shaft inserted extending outward from inside of the case 23 through the through hole 21, an insulated board 25 provided with an unillustrated electrically conductive pattern of resistance on the surface, a sliding contact 26 sliding on the electrically conductive pattern, a sliding contact retainer 27 holding the sliding contact 26 and secured on the operating shaft, a cover 28 attached at the opening 22 of the case 23, and a spring 29 mounted between the cover 28 and the sliding contact retainer 27.
The linear sliding variable resistor of the above-described configuration is assembled by the following procedure. First, the insulated board 25 is inserted from the opening 22 side of the case 23, then the operating shaft 24 is inserted into a through hole 30 provided in the sliding contact retainer 27. Subsequently, the operating shaft 24 and the sliding contact retainer 27 are inserted into the case 23 from the opening 22 side of the case 23, with its forward end being inserted into the through hole 21. Next, the spring 29 is inserted into the operating shaft 24 until the spring 29 comes into contact with the sliding contact retainer 27. Then, the cover 28 is attached to the case 23 with the rear end of the operating shaft 24 inserted into the through hole 31.
The sliding contact retainer 27 was a few millimeter small square part. Assembling the above-described conventional example of linear sliding variable resistor required time and labor, centering much of attention in supporting the small part firmly and inserting the operating shaft 24 into the through hole 30 measuring 1 to 2 mm in diameter, which is nearly the same as the operating shaft 24.